Laboratory of Feed Biotechnology, State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, P. R. China.
J Microbiol. 2012 Jun;50(3):452-8. doi: 10.1007/s12275-012-2051-3. Epub 2012 Jun 30.
The emergence of antibiotic resistance has spurred a great number of studies for development of new antimicrobials in the past decade. The purpose of this study was to screen environmental samples for Bacillus strains producing potent antimicrobial agents. A new strain, which showed strong antimicrobial activity against Staphylococcus aureus and Salmonella enterica ser. Pullorum, was isolated from soil and designated as B116. This new isolate was identified as Bacillus licheniformis by morphological, biochemical and genetic analyses. The production of bacteriocin-like substance (BLS) started at early exponential phase and achieved highest level at early stationary phase. The BLS was precipitated by ammonium sulfate and its molecular mass was determined as ∼4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Culture supernatant of the new isolate exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria, including Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Micrococcus luteus, Escherichia coli, and Salmonella spp. The BLS was resistant to heat, acid and alkaline treatment. Activity of the BLS was totally lost after digestion by pronase and partially lost after digestion by papain and lipase. The new isolate and relevant BLS are potentially useful in food and feed applications.
抗生素耐药性的出现促使过去十年中大量研究致力于开发新型抗菌药物。本研究旨在从环境样本中筛选产生强效抗菌剂的芽孢杆菌菌株。从土壤中分离到一株对金黄色葡萄球菌和鸡白痢沙门氏菌具有强烈抗菌活性的新型菌株，命名为 B116。通过形态学、生物化学和遗传学分析，该新分离株被鉴定为地衣芽孢杆菌。细菌素样物质（BLS）的产生始于指数早期，并在早期静止期达到最高水平。BLS 被硫酸铵沉淀，其分子量通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）确定为约 4 kDa。新分离株的培养液上清液对革兰氏阳性和革兰氏阴性菌均具有抗菌活性，包括蜡样芽孢杆菌、金黄色葡萄球菌、单核细胞增生李斯特菌、微球菌、大肠杆菌和沙门氏菌属。BLS 对热、酸和碱性处理具有抗性。经蛋白酶消化后，BLS 的活性完全丧失，经木瓜蛋白酶和脂肪酶消化后部分丧失。新分离株和相关 BLS 可能在食品和饲料应用中具有用途。
